Trench transistors are power transistors which have a gate electrode arranged in a trench in a semiconductor body and in which a direction of current flow runs in a vertical direction of a semiconductor body in which the transistor is integrated. Examples of such trench transistors are described in B. J. Baliga: Chapter 7.10.2 UMOS Structure, in: Power Semi-conductor Devices, PWS Publishing Company, Boston, 1995, pp. 412ff.
Such power transistors are used to switch voltages in the range from a few tens of volts to a few hundred volts and correspondingly large currents. The power loss which is inevitably converted into heat in the transistor during such switching operations causes the semiconductor body or semi-conductor substrate in which the transistor is integrated to heat up. In the extreme case, overheating may occur which damages the component itself and possibly also other components arranged in an assembly with the overheated component.
To protect a power transistor against inadmissibly high temperatures and hence against destruction by heat, it is known practice to record the temperature in the transistor's semi-conductor body and to take suitable action when a critical temperature is reached or exceeded, for example to switch off the component.
The temperature in a semiconductor body may be measured using both reverse biased and forward biased diodes. In this case, use is made of the fact that both the reverse current in a reverse biased diode and the voltage drop across a forward biased diode carrying a constant current have a pronounced temperature dependency, which means that these variables can be used to measure temperature.
However, there is still a need for a semiconductor component arrangement having a power transistor and a temperature measuring means comprising a temperature measuring resistor in which the temperature measuring resistor is simple to produce by means of technologies used for producing power transistors and has a high level of temperature sensitivity.